Silk and Silkworm

Silk is made from thread of silkworms. The fact that the word “silkworm” contains the word “silk” would imply that the worm was named after silk, but without the worm, we would have no silk. Does this mean that when they first made silk, they had no name for the worm, and they named the worm after the fact?

silk OE sioloc, seoloc "silk" ... ultimately from an Asian word (cf. Chinese si "silk", Manchurian sirghe, Mongolian sirkek) borrowed into Gk. as serikos "silken", serikon "silk". The use of -l- instead of -r- in the Balto-Slavic form of the word (cf. O.C.S. shelku, Lith. silkai) apparently passed into English via the Baltic trade and may reflect a Chinese dialectal form, or a Slavic alteration of the Greek word. Also found in O.N.

This is interesting, but there are other species that are named after their products, such as the walnut tree and the chinaberry tree. Arguably, this is true for all fruit trees as well, in English anyhow. I'd say that the cherry has a more prominent place in the language than the cherry tree, though in Japanese, of course, the fruit is named after the tree (which is known mostly for its blossoms, I'd say). See also "paper wasps," "honeybees," and perhaps "brewer's yeast"

Although in one sense it seems to be putting the cart before the horse to name the worm after the silk, in another, this is a perfectly reasonable example of naming a species after its most notable trait--and a luxury good from a worm is pretty notable.

A related animal name is "right whale"--so named because whale-hunters considered them the "right" whale to pursue.

Yes, in this case the cloth was known first. English 'silk' is from Latin 'serica', which is an adjective of the country it came from: Chinese cloth. Only in the Byzantine period were the mulbery bushes and silkworms introduced to the West.

The silkworm is so called because it's a worm that produces silk. Nothing odd about that.